Process for preparing 1-arylamino-2-methyl-anthraquinones



Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE PROCESS FOR PREPARING l-ARYLAMINO-Z- METHYL-AN THBAQUIN ONES No Drawing. Application February 19, 1930 Serial No. 429,830

27 Claims.

This invention relates to the synthesis of aryl derivatives of beta-methyl-anthraquinone and more particularly to the aryl-amine derivatives. Specifically the invention relates to the preparation of l-arylamino-2-methyl-anthraquinones.

The preparation of 1-arylamino-2-methylanthraquinones, according to prior art, has been generally the same as the preparation of l-anilino-anthraquinone. Usually it consists of a condensation of an arylamine with 1-chloro-2- methyl-anthraquinone in the presence of sodium carbonate or anhydrous sodium acetate and copper or some copper salt. The anhydrous condition is ordinarily maintained throughout the rei action. 7

This invention has as an object the improvement of the preparation of 1-arylamino-2- methyl-anthraquinones by condensing l-chloro- 2-methyl-anthraquinone with arylamines under jmore advantageous conditions than have been utilized heretofore. A further object is to produce purer products and higher yields of these compounds than has been possible in the processes of the'prior art. A still further object is to f preventexcessive side reactions in the aforesaid condensation. Other objects will appear hereinafter.

These objects are accomplished by the following "invention wherein 1 chloro 2 methyl- ;3(); anthraquinone is condensed with an arylamine in the 'presence of an alcohol or compound containing a'hydroxyl group.

' This invention will be readily understood by consideration of the following specific examples.

Example I To 600 parts of aniline are added 200 parts of 1-chloro-2-methyl-anthraquinone, 75 parts of anhydrous sodium acetate, 25 parts of copper sul j40 phate and parts of ethyl alcohol. The mixtureis then refluxed at a constant boiling temperature (95-105" C.) for a period of 15 to 20 hours, or until the I-chloro-2-methyl-anthraquinone completely disappears. When the reaction 45, is completed the product is allowed to cool to 20-30 C.; it is then filtered and washed with small amounts of aniline and alcoholand then with hot water until free of copper salts and sodium acetate. The residual l-anilino-Z-methylanthraquinone consists of chocolate-brown, long needle-like crystals, characteristic of a pure product.

7 Example II To 600 parts of para-toluidine are added 200 parts of 1-chloro-2-methyl-anthraquinone, parts of anhydrous sodium acetate, 25 parts of copper sulphate and 50 parts of ethyl alcohol. The mixture is then refluxed at a constant boiling temperature (95-105" C.) for a period of 15 to 6Q Example III To 600 parts of ortho-anisidine are added 200 7 parts of 1-ch1oro-2-methy1-anthraquinone, '75 parts of anhydrous sodium acetate, 25 parts of copper sulphate and 50 parts of ethyl alcohol. The mixture is then refluxed at a constant boiling temperature (95-105 C.) for a period of 15 to 75 20 hours, or until the 1-chloro-2-methyl-anthraquinone completely disappears. When the reaction is completed the product is allowed to cool to 20-30 C.; it is then filtered and washed with small amounts of solvent naphtha and alcohol and then with hot water until free of copper salts and sodium acetate.

Example IV To 600 parts of para-phenetidine are added 200 35 parts of 1-chloro-2-methyl-anthraquinone, '75 parts of anhydrous sodium acetate, 25 parts of copper sulphate and 50 parts of ethyl alcohol. The mixture is then refluxed at a constant boiling temperature (-105 C.) for a period of 15 to 9Q 20 hours, or until 1-chloro-2-methyl-anthraquinone completely disappears. When the reaction is completed the product is allowed to cool to 20-30 C.; it is then filtered and washed with small amounts of solvent naphtha and alcohol 95 and then with hot water until free of copper salts and sodium acetate.

The disappearance of 1-chloro-2-methylanthraquinone is readily determined by means of a spot test on a glass slide when examined under a microscope. The starting compound occurs as white crystals, whereas the product of the reaction gives crystals which are colored.

Various modifications may be made and equivalent materials used without detriment to the process. As shown by the examples; in the place of aniline, thevarious toluidines, anisidines, phenetidines, etc. may be substituted. The invention is not limited to the use of ethyl alcohol since unsaturated alcohols, poly-hydroxy alcohols, and even mixtures of alcohols may be used. It is also possible to use alcohol mixed with water or to use Water alone. Specific examples of other aliphatic alcohols are methyl, butyl and amyl. The boiling point of the alcohol used is an important factor and too high a boiling point should be avoided. The process is preferably limited to Water soluble alcohols to aid in the washing of the product resulting from this invention. The use of a single alcohol is preferred. Especially good results have been obtained with ethyl alcohol alone. The process is not limited to chloro-methyl anthraquinone since other halogen derivatives may be used. Similarly the process is not limited to 1-halogen2-methyl-anthra quinones since other alkyl groups may be substituted for the methyl. In addition other copper salts or copper itself may be used to facilitate the reaction and any material capable of reacting With the liberated halogen acid may be substituted for the sodium acetate, governed, of course, by non reactiveness to the other constituent parts of the r action mixture.

When aniline or its homologues are condensed with l-chlcro-Z-methyl-anthraquinone, due to the position of the methyl group in respect to the chlorine group, the reaction has strong tendency to proceed in such a manner to involve the methyl roup to form ethene and other complexes. The alcohol present varying quantities acts as a bufier to prevent such side reactions and at the time aids in securing smoother operation. The above state- "ment of theory of operation is given merely to aid in the understanding of the invention and applicant does not desire to be limited thereby.

This invention insures a -60% overall yield of l-aniline-2-methyl-anthraquinone as compared with 40-45% yield of previously known and tried methods. The reaction is easily controlled because the aniline and alcohol form a constant boiling mixture. Furthermore, it eliminates side reactions to a much larger extent than has been possible heretofore, and in addition insures a uniform, pure product.

As many apparently widely different embodiments of this invention maybe made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. The method of producing l-aryl-amine-Z- alkyl-anthraquinones which comprises refluxing an aryl-amine and a 1-chloro-Z-allryl-anthraquinone in the presence of a copper salt, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 109 C., thereafter cooling to about 20- 5 C. and separating the 1-aryl-amine-2-alkyl-anthraquinone formed.

2. In the production of l-anilinc-2-methyl-- anthraquinone the step of reflu g a mixture of 1-chloro-2-methyl-anthraquinone and aniline in the presence of copper sulfate, ethyl alcohol, and anhydrous sodium acetate.

3. In the production of l-anilino-2-methylanthraquinone the step of refluxing a mixture of l-chloro-Z-methyl-anthraquinone and aniline in the presence of a copper salt, ethyl alcohol, and anhydrous sodium acetate.

4. In the production of l-anilino-Z-methylanthraquinone the step of refluxing a mixture of l-chloro-2-methyl-anthraquinone and aniline in the presen e of a copper substance, an alkylalcohol, and anhydrous sodium acetate.

5. In the production of l-anilino-2-methylanthraquinone the step of refluxing a mixture of 1-chloro-Z-methyl-anthraquinone and aniline in the presence of copper sulfate, ethyl alcohol, and sodium acetate.

6. The process comprising heating a mixture containing aniline, a copper salt, an alcohol, and an alkali-metal acetate with l-chloro-Z-methylnthraquinone at about 95-105" C. and thereafter separating the anthraquinone derivative formed.

7. The process comprising heating a mixture including an arylamine, a copper salt, an alcohol, and an alkali-metal acetate with l-chloro-2- methyl-anthraquinone at about 95-105 C.

8. The process comprising heating a mixture containing aniline, a copper salt, an alcohol and an alkali metal salt of an aliphatic acid with l-chloro-2 methyl-anthraquinone at about 95- 105 C. and thereafter separating the anthraquinone derivative formed.

9. The process comprising heating a mixture containing aniline, a copper salt, an alcohol, and

an allzalimretal acetate with l-halogen-Z-alkyh anthraquinon at about SEE-105 C. and thereafter separating the anthraquinone derivative formed.

10. The process com rising heating a mixture containing aniline, a copper salt, ethyl alcohol, and .an alkali metal acetate with 1-chloro-2- methyl-anthraquinone at about 95-105 C. and thereafter separating the anthraquinone derivative formed. V

11. The preparation of l-aryl-amine-Z-alkylanthraquinones comprising reacting of I l-halogen-2-alkyl-anthraquinone with an anisidine in the presence of an alcohol under the influence of heating.

12. The preparation of l-aryl-amine-2-alkylanthraquinones comprising reacting l-chloro-Z- methyl-anthraquinone with a toluidine in the presence of an alcohol under the influence of heating.

13. The preparation of l-aryl-amine-Z-alkyl anthraquinones comprising reacting 1-ch1oro-2 alkyl-anthraquinonewith a phenetidine in the presence of an alcohol under the influence of heating. p p

14. The preparationof l-aryl-amine-Z-alkylanthraquinones comprising reacting 1-halogen- Z-alkyl-anthraquinone with a phenyhamine in the presence of an alcohol under the influence of heating.

15. The presence of l-aryl-amine-Z-alkylanthraquinones comprising reacting l-halogen- 2-alkylanthraquinone with an aryl -amine in the presence of a material comprising ethyl alcohol under the influence of heating.

16. The preparation of l-aryl-amine-Z-alkylanthraquinones comprising reacting l-halogen- Z-alkyl-anthraquinone with an aryl-amine in the presence of ethanol under the influence of heatmg.

1'7. The preparation of I-aryLamine-Z-alkylanthraquinones comprising reacting l-halogen- 2-alkyl-anthraquinone with aniline in the presence of an alcohol under the influence of heat- 18. The method of preparing l-anilino-Z- methyl-anthraquinone which comprises adding fifty (50) parts of ethyl alcohol, twenty-five (25) parts of copper sulfate, seventy-five ('75) parts of anhydrous sodium acetate and two hundred (200) parts of 1-chloro-2-methyl-anthraquinone to six hundred (600) parts of aniline and refluxing the mixture until the 1-chloro-2-methylanthraquinone disappears, thereafter cooling to a temperature of 2030 C. and separating the resultant 1-anilino-2-methyl-anthraquinone.

19. The process which comprises refluxing a lhalogen-Z-alkyl-anthraquinone and an aryl amine in the presence of a copper substance, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

20. The process which comprises refluxing a 1-chloro-2-alkyl-anthraquinone and an aryl amine in the presence of a copper substance, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

21. The process which comprises refluxing a 1-halogen-2-alkyl-anthraquinone and an aryl amine in the presence of a copper substance, an ethyl alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

22. The process which comprises refluxing a 1-halogen-2-alkyl-anthraquinone and an aniline in the presence of a copper substance, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

23. The process which comprises refluxing a 1- chloro-2-alkyl-anthraquinone and an aniline in the presence of a copper substance, an ethyl alcohol and an alkli metal salt of a saturated fatty acid at a temperature of about 100 C.

24. The process which comprises refluxing a 1-halogen-2-alkyl-anthraquinone and an aryl amine in an amount greatly in excess of that required to molecularly combine with the anthraquinone compound and in the presence of a copper substance, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

25. The process which comprises refluxing a 1-halogen-2-alky1-anthraquinone and an aryl amine in an amount greatly in excess of that required to molecularly combine with the anthraquinone compound and in the presence of a copper substance, an ethyl alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

26. The process which comprises refluxing a 1-halogen-2-substituted-anthraquinone and an aryl amine in the presence of a copper substance, an alcohol and an alkali metal salt of a saturated fatty acid at a temperature of about 100 C.

27. The method of producing 1-aryl-amine-2- alkyl-anthraquinones which comprises heating an aryl amine and a 1-halogen-2-alkyl-anthraquinone in the presence of a copper substance from ethyl alcohol and an alkali metal compound capable of reacting with a hydrogen halide, at a temperature of 95 to 105 C.

ALEXANDER J. WUERTZ. 

